Who uses distilled water per their owners manual 4 refractometer calibration?

Im wonderin who has used distilled water for calibrating their refractometer? My milwaukee instructions say to use it.

 

I use it with ours . Tho most recommend getting a calibration solution . I use it and have had no issues , I cross refrenced it with a digital lab that I had calibrated . I honestly believe that once you get it and test your spg (if you use the premeasured ammount ) it should be near spot on what you mixed .. IE we mix for 10 gallons using RC salt it always shows 1.025 and 0 for the distilled that we have ...

 

Inwall (Curt) has already started a thread on this. Try using the search to find your answer, there is a ton of knowledge in the archives if you just take time to look.

http://www.3reef.com/forums/general-reef-topics/refractometer-calibration-38022.html

 

Your refractometer will be more accurate if you calibrate to 53 microsiemens. American Marine Pinpoint 53 mS fluid is inexpensive and works perfectly. Basically you calibrate to 35 ppt salinity/1.0264 specific gravity vs calibrating to zero with distilled. In fact, after proper calibration, most people's refracts will not read zero when using distilled afterwards.

Here's the nitty gritty Refractometers and Salinity Measurement by Randy Holmes-Farley - Reefkeeping.com

Here's the Cliff's Notes Version:

Most people's refractometers are not made for Natural Saltwater (NSW)....they are made for Sodium Chloride. So when you calibrate with RO/DI water or Distilled Water you are calibrated for NaCL only. Unfortunately NSW has all sorts of addition ions besides NaCl.

Is it really a big deal? Not in my opinion because stability is more important than the actual number. If I don't think it's a big deal, why did I even bring this up? Well, my reef club bought 53 mS fluid, and we all brought in our refracts. Some people matched both ways, some peoples refracts were off by a little bit. However, a couple of people had refracts that were off by a LOT.